The invention discloses a genetically engineered bacterium and a method for preparing a fucosylated oligosaccharide using the same. The method includes: transferring a fucosyl group of a donor to an oligosaccharide receptor by a fucosyltransferase heterologously expressed in a genetically engineered bacterium; wherein the donor is a nucleotide-activated donor, the fucosyltransferase has ?-1,2-fucosyltransferase activity; wherein, the fucosyltransferase is selected from one or more of the enzymes corresponding to NCBI Accession Numbers WP_109047124.1, RTL12957.1, MBP7103497.1, WP_120175093.1, RYE22506.1, WP_140393075.1 and HJB91111.1. The preparation method of the invention has high yield, greatly improved substrate conversion rate and product conversion rate, and has the potential to be applied to industrial production.

The present invention relates to primarily genetically modified microorganisms for in vivo synthesis of lacto-N-tetrose (LNT) and lacto-N-neotetrose (LNnT), and their fucosylated derivatives, and to uses of such microorganisms in methods of producing lacto-N-tetrose and lacto-N-neotetrose, and their fucosylated derivatives.

The present invention belongs to the technical field of biochemistry, and in particular relates to an efficient enzymatic synthesis method for a holothurian glycosaminoglycan. The present invention establishes an efficient enzymatic synthesis route for the holothurian glycosaminoglycan, in which the holothurian glycosaminoglycan with anticoagulant activity is efficiently synthesized through a one-pot multienzymatic strategy using sulfated fucose and chondroitin sulfate as substrates and catalyzed by -1,3-fucosyltransferase mutant and L-fucokinase/GDP-fucose pyrophosphorylase, which provides important technical support for the development of new anticoagulant drugs.